Electronic musical instrument capable of providing a third type of musical tones by operation of two keyboards in addition to the ordinary melody and chord tones

ABSTRACT

In an electronic musical instrument equipped with a first keyboard for melody performance and a second keyboard for chord performance, operation of the first keyboard is detected directly or indirectly by a detector to produce a control or detection signal. Tone signals derived from the tone generators by operation of the second keyboard are branched to a gate which is enabled by the control signal so as to cause operation of both first and second keyboards to attain the production of a third type of musical tones in addition to the ordinary melody and chord tones. Output tone signals from the gate may be supplied with a sustaining or percussive envelope and modulated in amplitude or frequency.

Okamotof 1 ELECTRONIC MUSICAL INSTRUMENT I I 1111 3,825,668 1 July 23, 1974 3,553,335 Bunger l, 124 103 CAPABLEOF PROVIDING A THIRD TYPE lii/ Gdgcm r 84/ 1.26 OF MUSICAL TONES BY OPERATION or 3671659 6/1972 jif KEYBOARDS IN ADDITION To THE '3I697I664 10 1972 Hiyama III: I: 84/1I17 ORDINARY MELODY AND CHORD TONES 3,708,602 1/ 1973 Hiyama 84/1.03

[75] Inventor: Shimaji Okamoto, Hamamatsu,

Japan 3,725,560 4/1973 1 gneez Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu-shi,

ShizubkwkenJaPan 3,775,545 11/1973 Tsukamoto et al. 134/101 [22] Filed: May 1973 Primary ExaminerRichard B. Wilkinson [21] A pL N 364,257 Assistant Examiner-Stanley J. Witkowski 6 Attorney, Agent, or FirmFlynn & Frishauf [30] Foreign Application Priority Data May 30, 1972 Japan 4753551 ABSTRACT v May 30, 1972 Japan 47-53552 In an electronic musical instrument q pp with a 1972 Japan 47'53553 first; keyboard for melody performance and a second May 30, 1972 Japan "47-53554 keyboard r chord p o Operation of thg first keyboard is detected directly or indirectly by a detec- [52] US. Cl 84/1.17, 84/1.13, 84/1.22, tor to produce a control of detection Signal. o 5 1 I Cl 84/ 1 nals derived from the tone generators by operation of 1 uf econ y r a branched to a g is [58] searchmw" 1 enabled by the control signal so as to cause operation 8 124.7126" 23 of both first andsecond keyboards to attain the pro- 5 6 duction of athird type of musical tones in addition to 1 1 References cued the ordinary melody and chord tones. Output tone sig- UNITED STATES PATENTS nals from the gate may be supplied with a sustaining 2,583,566 1/1952 Hanert 84/ 1.17 or percussive envelope and modulated in amplitude or 3,215,767 ll/l965 Martin 84/1.24 frequency. 3,247,310 4/1966 Stinson 84/l1l7 3,538,806 11/1970 Hunger '84/122 X 16 Claims, 9 Drawing Figures F'RST 58851166 KEYER FILTERS l2 I 21 DETECTOR TONE 1 A 212 T N GENETATORS GATE -C8L5RINC .14 5 FILTERS 1 H 5 2b 17' 18 SECOND 5885mm 4 Y FILTERS H PATENTEUJULZBIBH SHEET 10$ 3 FIG.

TONE

COLORIN FILTERS TON FILTERS 1H TONE COLORING Q FILTERS,

GATE -COL5RINC 24% DETECTOR f SECOND KEYER TONE GENERATORS A lllllll/llllllllllllllllllfllllll" FIG. 2{

Flefz- INPUT OUTPUT DETECTOR INSTRUMENT CAPABLE TONES BY OPERATION OF TWO KEYBOARDS IN ADDITION TO THE ORDINARY MELODY AND CHORD TONES This invention relates to an electronic musical instrument and more particularly to an electronic musical instrument in which melody-tones control the manner in which chord tones are produced.

An electronic musical instrument generally has a first orupper'keyboardmainly for melody performance and a second or lower keyboard for chord performance. The upper keyboardv is operated mainly by the right hand and the lower keyboard mainly by the left hand. In actual performance, however, the right hand is sometimes used in performing a melody through chords. Melody and chord performances on the upper keyboard alone demands va relatively advanced performance skill. Accordingly, it is difficult for the beginner to enjoy melody and chord performances by operating the upper keyboard alone. I g It is accordingly the object of this invention to provide an electronic musical instrument which, where chords are played by the left hand and also melody tones by the right hand, can control the production of chords in exact timing with the melody tones, thereby enabling even the beginner fully to enjoy various types of performance.

suM Rv OF THE INVENTION According to an aspect of this invention, there is provided an electronic musical instrument which cornprises an electronic musical instrument comprising a first keyboard provided with a plurality of keys'and adapted mainly for melody performance; a second keyboard provided with a plurality of keys and adapted mainly for chord performance; a plurality of tone gentone generators for selectively deriving the signals from the tone generators in response to keyoperation on the second keyboard; detection means for detecting the operation of the first keyboard to produce a control signal; and'at least one gate means having input, output and control terminals, the input terminal of the gate means being connected to receive at least portion of output signals from the second keyer means, the control terminal of the gate means being connected to re- Ceive the control signal whereby the gate means is enabled in response to the control signal to conduct the input tone signal from the input terminal to the output terminal. Further, means is provided toconvert the electrical signals into audio signals.

BRIEF DES'CRIPTION OF THE DRAWINGS,

FIG. is a block diagram of an electronic musical instrument according: to an embodiment of this invention;

FIGS. 2A and 2B illustrate the envelopes of tone signals obtained from the gate of FIG. 1;

FIGS. 3, 4. and 5 illustrate a concrete circuit arrangemerits of the detector and gate of FIG. 1;,

FIG. 6 is a block diagram of an electronic musical instrument according to another embodiment of the invention;

FIGS. 7 and 8 show the waveforms of signals by way of illustrating the operation of the electronic musical instrument of FIG. 6; and

' FIG. 9 is a modification of the embodiment. of FIG. L h

DETAILED. DESCRIPTION OF ILLUSTRATED EMBODIMENTS coloring filters 16'to an amplifier 17 followed by a loudspeaker 18; Tone signals obtained from the second keyer 14 are supplied to the amplifier 17 through second tone coloring filters 19.

The above arrangement is the same as that of the prior art electronic musical instrument. In this invention, however, at least part of the output signals from the second keyer 14 is supplied to a gate 20,-which normally remains nonconducting, but which becomes con- I ducting by operation of the first keyboard 13, i.e., upon receipt of a control signal from the later described detector 21 for detecting tone signals derived from the first keyer 12 by operation of the first keyboard 13. Tone signals passing through the gate 20 are conducted to tone coloring filters 22, which may be'designed' to have different tone color characteristics from those of the first and second tone coloring filters '16 and 19.

The electronic musicalfin'strument of this invention arranged as described above provides chord tones synchronized with the rise of melody tones in addition to the ordinary melody and chord tones produced by operation of the first and second keyboards l3 and 15,

respectively. Namely, this invention attains the generation of three different types of musical tones by key operation with two hands, enabling even a beginner to carry out a great variety of performances.

boards and a pedal keyboard or combining the right andleft sections of a single keyboard, in case an electronic musical instrument is only provided with such a single keyboard. The Output of the gate 20 may be coupled to both or either of the first and second tone coloring filters l6 and 19 instead of to the third tone coloring filter 22.

While the second keyer 14 generally generates a plurality of tone signals having different feet such as 4 and 8, it is possible to supply the gate 20 with an output signalsuch as a 4 feet tone signal from the second keyer 14 or with the same tone signals as those conducted to the second tone coloring filters 19.

The gate 20 may be so arranged that while at least one key of the first keyboard 13 is operated, an output signal therefrom is controlled by the detector 21 to have a substaining envelope shown in FIG. 2A or a percussive envelope illustrated in FIG. 2B which sharply rises and then attenuates.

sive envelope provide chord tones which will impress the listener with a feeling of more distinct rhythm.

FIG. 3 illustrates the circuit arrangement of the detector 21 and gate 20 for directly detecting the operation of the first keyboard 13 and enabling the gate 20 to produce an output tone signal having a percussive envelope indicated in FIG. 2B. This circuit arrangement includes key switches S1, S2 for directly detecting the operation of the first keyboard 13. Across a power source in series with the key switches S1, S2 are connected common resistors and trigger signal generating circuits T1, T2 each having a resistor R1 andcapacitor C1 connected in parallel with each other. A monostable multivibrator including a normally nonconducting transistor Trl, a normally conducting transistor .Tr2 and associated resistors and capacitors is triggered by a trigger signal supplied to the base of the transistor Trl by operation of the first keyboard 13, causing an output. signal having'a predetermined pulse width to be generated from the collector of the transistor Tr2. An output signal from the monostable multivibrator is amplified which includes transistor by a buffer amplifier Tr3, and its associated resistors,jan output from which in turn is differentiated by a differentiation circuit comprising a capacitor C2 and resistor R2. A diode D causes the differentiation circuit to produce only a positive going differentiated pulse having a percussive envelope, the pulse being supplied to the gate of a field effect transistor Tr4 which along with-its associated resistors comprises the gate 20, to render the field effect transistor Tr4 conducting. The source of the field effect transistor Tr4 is supplied with an input tone signal from the second keyer 14. When the field effect transistor Tr4 is enabled, the tone signal is fed out from the drain thereof. A potentiometer P is provided to adjust the bias voltage of the gate of the field effect transistor Tr4. Upon receipt of a gate bias voltage supplied by the potentiometer P, the field effect transistor Tr4 becomes nonconducting. When the voltage of a positive going pulse delivered from the aforesaid differentiation circuit is added to the gatebias voltage, then the field effect transistor Tr4 is rendered conducting. The resistor R2 may comprise, as indicated in FIG. 3, a potentiometer so as to adjust the level of a differentiated pulse. As is well known, the level of the voltage impressed onthe gate of the field effect transistor Tr4 controls the conductivity of a conduction path defined between the source and drain of the field effect transistor Tr4. Accordingly, the field effect transistor Tr4 whose gate is supplied with a control signal having a percussive envelope produces from its drain a tone signal having a percussive envelope shown in FIG. 23.

FIG. 4 illustrates the circuit arrangement of a detector 21 and gate 20, in which the output signal from the gate has a sustaining envelope as shown in FIG. 2A using tone signals derived from the first keyer 12 by operation of the first keyboard 13. Tone signals from the first keyer 12 are amplified by an amplifier including a transistor TrS and its associated circuitry and then subjected to half-wave rectification by a transistor Tr6. A half-wave rectified output is smoothed by a lowpass filter comprising a capacitor C3 and resistor R3. A control signal thus smoothed is supplied via potentiometers to the gate of the field effect transistor Tr4 with the age.

FIG. 5 is the circuit arrangement of a detector 21 and gate 20, in which the output signal from the gate has a percussive envelope as shown in FIG. 2B using tone signals derived from the first keyer 12 by operation of the first keyboard 13. Tone signals from the first keyer 12 are amplified by an amplifier including a transistor 7 and its associated circuitry and further subjected to half-wave rectification by a transistor 8. A half-wave rectified output is smoothed by a capacitor C4 and amplified by an amplifier including a transistor 9. An output from the transistor Tr9 is differentiated by the capacitor C5 and a variable resistor VR for adjusting the time constant and voltage level. A differentiated output is supplied to the gate of the field effect transistor Tr4 with the voltage of the output added to the gate bias voltage, causing a tone signal to be fed out from the drain of the field effect transistor Tr4 with the sustaining envelope.

The embodiment of FIG. 1 only allows a tone signal delivered from the gate 20 to have a sustaining or percussive envelope. However, this process sometimes provides a monotonous musical effect. The embodiment of FIG. 6 is intended to provide a variety of performances by furnishing an output from the gate 20 with tremolo, vibrato or other musical effects. In FIG. 6, there are provided on the output side of tone coloring filters 22 a modulator 23 and an oscillator 24 for supplying a modulating signal to the modulator 23. The modulator 23 may comprise an amplitude modulator, frequency modulator or a known tone color modulator for producing, for example, a wow-wow effect.

The embodiment of FIG. 6 includes a second gate 25, output signals from which are conducted through tone coloring filters 26 to the modulator 23. The first and second gates 20 and 25 may be designed to enable out put signals from the second keyer 14 to have percussive and sustaining envelopes respectively in response to a control .signal from the detector 21. Since such arrangements of gates 20 and 25 to provide percussive and sustaining envelopes are already known, a detailed description thereof is omitted. It is obviously possible to combine the embodiments of FIGS. 4 and 5 or FIGS. 3 and 4 in supplying percussive and sustaining envelopes to tone signals.

It is preferred that tone volume or stop switches 27 and 28 be disposed on the outputsides of the first and l illustrated in FIG. 8A. Where outputs from the gates 20 and 25 are mixed in an equal ratio through adjustment by the tone volume or stop switches, then the modulator 23 is supplied with a tone signal having an envelope shown in FIG. 7B and generates a tone signal furnished with a tremolo effect represented by an envelope shown in FIG. 8B.

As mentioned above, the embodiment of FIG. 6 produces a third type of musical tones furnished with special musical effects in addition to the ordinary melody and harmonic tones, thereby providing a great variety of performance by the ordinary simple operation of an electronic musical instrument.

v FIG. 9a amodification 1. A plurality of detectors 21A, 21B, 21C ,.'are pro- C respectively.

of the embodiment of FIG.

vided so as to match a plurality of compasses of the first keyboard 13. Further, a plurality of gates 20A, 20B,

20C are arranged to correspond to the plural detectors 21A, 21B, 21C

The first keyboard 13 may be separated into a plurality of one octave divisions, such as C1 to B1, C2 to B2,

. C3 to 133...; Where any of the keys included in the di vision C1 to B1 is operated, the detector 21A generates -a detection signal. By operation of the second keyboard pressed on the first keyboard 13. Then the detector 21B produces a detection signal to actuate .the gate 208; thereby supplying the third tone coloring filters22 with 8 tone signals corresponding to the notes Cl, E1 and G1. Where, in this case, the key of the note C3 is depressed on he first keyboard 13 while the aforesaid chord represented by the notes Cl, E1 and G1 is per- .formed, then the detector 21C generates a detection signal to actuate the gate 20C, thereby the third zone coloring filters 22 with 4' tone signals corresponding to the aforesaid notesClQEl and G1.

The embodiment of FIG. 9 enables a third type of musical tones to be produced by operation of the second keyboardlS in exact timing with that of the first keyboard 13' and with pitches corresponding to those obtained on said keyboard 13. If, therefore, a proper selection is'made of the levels and colors of the'third type of musical tones as well as the envelope characteristics of the'gates, then a great variety of performance .will be attained by operating the first and second keyboards 13 and 15 alone. Particularly, the third type of musical tones have their-frequency varied with the compass played on the first keyboard 13, producing very musically effective chord tones. t t What is claimed-isi 1. An electronic musical instrument comprising: 1- a first keyboard means provided with a plurality of keys; a second keyboard means provided with a plurality of keys; a plurality of tone generators; r a first keyer-means'coupled to said first keyboard means and to said tone generators for selectively deriving tone signals from said tone generatorsin response to key operation on said first keyboard; a'second keyer means coupled to said second keyboard means and to said tone generators for selectively deriving tone 'signals'from said tone genera tors in response to keyboard; t t

detection means coupled to said first keyboard key operation on said second tion means to receive said control signal whereby said gate means is enabled in'response to said control signal to conduct the input tone signal from said input terminal of said gate means to said output terminal of said gate means; and

means coupled to the outputs of said gate means and to the outputs of said first and second keyer means for producing an audio signal corresponding to the electrical signals fed thereto. 2. An electronic musical instrument according to claim 1 wherein:

said detection means produces said control signal with a percussive envelope; and

said gate means includes 'a-field effect transistor having a drain and a source defining a conduction path therebetween and a gate receiving said control signal.

3, An electronic musical instrument according to claim 1 wherein:

said detection means produces said control signal with a sustaining envelope and I Said gate means includes a field effect transistor having a drain and a source defining a conduction path therebetween and a gate receiving said control sig nal.

.4. An electronic musical instrument according to claim 1 wherein said detection means includes:

a plurality of key switches actuated by operation of said keys of said first keyboard;

a plurality of trigger signal generator means coupled to said key switches for producing atrig'ger signal when at least one key switch-is actuated;

means coupled to said trigger signal generator means for producing a pulse signal having a predetermined pulse width in response to said trigger signal;

and means coupled to said pulse signal generator means for differentiating saidpulse signal to generate said a control signal-having a percussive envelope. 5. Anelectronic musical instrument according to claim 1 wherein said detection means includes:

means for amplifying output signals from said first keyer means;and arectifying circuit for rectifying theoutput signals from said amplifying means to produce a control signal having a sustaining envelope. 6. An electronic musical instrument according to claim 1 wherein said detection means includesi means for amplifying output signals from said first keyer means; v means coupled tosaid, amplifying means for rectifying output signals from said amplifying means; and a differentiation circuit coupled to said rectifying means for differentiating an output signal from said rectifying means to generate a control signal having a percussive envelope.

7. 'An electronic musical instrument according to claim 1 further comprising means connected to receive an output signal from said'gate means for modulating said gate means output signal.

8. An electronic musical instrument according to claim 1 wherein said gate means includes at least a first and a second gate circuit, said first gate circuit imparting a percussiveenvelope to an output signal from said second keyer means in response to said control signal from said detection means, and said second gate circuit imparting a sustaining envelope to said output signal from said second keyer means in response to said control signal from said detection means.

9. An electronic musical instrument according to claim 8 further comprising means coupled to receive output signals from said first and second gate circuits for modulating said output signals.

10. An electronic musical instrument according to claim 9 further comprising:

a first stop switch coupled between said modulating means and said first gate circuit and a second stop switch coupled between said modulating means and said'second gate circuit.

11. An electronic musical instrument according to claim 1 wherein:

said detection means comprises a plurality of detection units so arranged as to match a plurality of compasses of said first keyboard; I

said gate'means includes a plurality of gate circuits so provided as to correspond to said plural detection units; and

said second keyer means has a plurality of outputs for coupling out tone signals having different feet, said plurality of outputs being connected to the input terminals of respective ones of said plurality of gate circuits.

12. An electronic musical instrument according to claim 11 wherein said first keyboard is separated into a plurality of one-octave compasses.

13. An electronic musical instrument according to claim 1 wherein output signals from the first and second keyer means and gate means are coupled to first, second and third tone coloring filters means respectively.

14. An electronic musical instrument according to claim 9 further comprising:

a first volume control means coupled between said modulating means and said first gate circuit and a second volume control means coupled between said modulating means and said second gate circult.

15. An electronic musical instrument according to claim 1 wherein said first keyboard is adapted for mel- I ody performance and said second keyboard is adapted for chord performance.

'16. An electronic musical instrument according to claim 1 wherein said detection means is coupled to said first keyboard means through said first keyer means, said detection means detecting operation of said first keyboard means by detecting outputs from said first keyer means. 

1. An electronic musical instrument comprising: a first keyboard means provided with a plurality of keys; a second keyboard means provided with a plurality of keys; a plurality of tone generators; a first keyer means coupled to said first keyboard means and to said tone generators for selectively deriving tone signals from said tone generators in response to key operation on said first keyboard; a second keyer means coupled to said second keyboard means and to said tone generators for selectively deriving tone signals from said tone generators in response to key operation on said second keyboard; detection means coupled to said first keyboard means for detecting the operation of said first keyboard to produce a control signal; at least one gate means having input, output and control terminals, said input terminal of said gate means being coupled to said second keyer means to receive at least a portion of output tone signals from said second keyer means, said control terminal of said gate means being coupled to said detection means to receive said control signal whereby said gate means is enabled in response to said control signal to conduct the input tone signal from said input terminal of said gate means to said output terminal of said gate means; and means coupled to the outputs of said gate means and to the outputs of said first and second keyer means for producing an audio signal corresponding to the electrical signals fed thereto.
 2. An electronic musical instrument according to claim 1 wherein: said detection means produces said control signal with a percussive envelope; and said gate means includes a field effect transistor having a drain and a source defining a conduction path therebetween and a gate receiving said control signal.
 3. An electronic musical instrument according to claim 1 wherein: said detection means produces said control signal with a sustaining envelope and said gate means includes a field effect transistor having a drain and a source defining a conduction path therebetween and a gate receiving said control signal.
 4. An electronic musical instrument according to claim 1 wherein said detection means includes: a plurality of key switches actuated by operation of said keys of said first keyboard; a plurality of trigger signal generator means coupled to said key switches for producing a trigger signal when at least one key switch is Actuated; means coupled to said trigger signal generator means for producing a pulse signal having a predetermined pulse width in response to said trigger signal; and means coupled to said pulse signal generator means for differentiating said pulse signal to generate said control signal having a percussive envelope.
 5. An electronic musical instrument according to claim 1 wherein said detection means includes: means for amplifying output signals from said first keyer means; and a rectifying circuit for rectifying the output signals from said amplifying means to produce a control signal having a sustaining envelope.
 6. An electronic musical instrument according to claim 1 wherein said detection means includes: means for amplifying output signals from said first keyer means; means coupled to said amplifying means for rectifying output signals from said amplifying means; and a differentiation circuit coupled to said rectifying means for differentiating an output signal from said rectifying means to generate a control signal having a percussive envelope.
 7. An electronic musical instrument according to claim 1 further comprising means connected to receive an output signal from said gate means for modulating said gate means output signal.
 8. An electronic musical instrument according to claim 1 wherein said gate means includes at least a first and a second gate circuit, said first gate circuit imparting a percussive envelope to an output signal from said second keyer means in response to said control signal from said detection means, and said second gate circuit imparting a sustaining envelope to said output signal from said second keyer means in response to said control signal from said detection means.
 9. An electronic musical instrument according to claim 8 further comprising means coupled to receive output signals from said first and second gate circuits for modulating said output signals.
 10. An electronic musical instrument according to claim 9 further comprising: a first stop switch coupled between said modulating means and said first gate circuit and a second stop switch coupled between said modulating means and said second gate circuit.
 11. An electronic musical instrument according to claim 1 wherein: said detection means comprises a plurality of detection units so arranged as to match a plurality of compasses of said first keyboard; said gate means includes a plurality of gate circuits so provided as to correspond to said plural detection units; and said second keyer means has a plurality of outputs for coupling out tone signals having different feet, said plurality of outputs being connected to the input terminals of respective ones of said plurality of gate circuits.
 12. An electronic musical instrument according to claim 11 wherein said first keyboard is separated into a plurality of one-octave compasses.
 13. An electronic musical instrument according to claim 1 wherein output signals from the first and second keyer means and gate means are coupled to first, second and third tone coloring filters means respectively.
 14. An electronic musical instrument according to claim 9 further comprising: a first volume control means coupled between said modulating means and said first gate circuit and a second volume control means coupled between said modulating means and said second gate circuit.
 15. An electronic musical instrument according to claim 1 wherein said first keyboard is adapted for melody performance and said second keyboard is adapted for chord performance.
 16. An electronic musical instrument according to claim 1 wherein said detection means is coupled to said first keyboard means through said first keyer means, said detection means detecting operation of said first keyboard means by detecting outputs from said first keyer means. 